1. The Field of the Invention
This invention relates to seat belt devices and more particularly to that class of apparatus which is automatically openable upon an impact suffered by the vehicle carrying the seat belt apparatus.
2. Description of the Prior Art
The prior art abounds with safety belt catches and operating devices. U.S. Pat. No. 3,494,664 issued Feb. 10, 1970 to John D. States teaches a latch or anchoring mechanism for an automobile safety belt having an anchoring structure located in the crease between the seat portion and back portion of a bench type seat, and a buckle portion fastened to the belt webbing and detachably connectable to the anchoring structure. The anchoring structure includes two bail members parallel to and spring pressed toward each other, but capable of moving laterally away from each other. The buckle portion has a main member with a pointed end and with square shoulders behind the pointed end. When the pointed end is pushed into the anchoring structure, it cams the bail members apart, and they snap behind the square shoulders on the main member, securing it against removal. A release slide on the main member has a cam portion which separates the anchoring bail members from each other when the release slide is moved longitudinally relative to the main member of the buckle portion, thus releasing the bail members from the square shoulders of the buckle portion and allowing the buckle portion to be withdrawn from the anchoring structure. The States apparatus requires manual engagement as well as manual disengagement of the coupling portions of the apparatus, thereby precluding the ability of a seriously injured person from being able to be released from a vehicle when such person is unconscience and unable to release himself from the belt apparatus.
German Pat. No. 2,401,441 issued July 17, 1975 to K. Metzger describes a separate emergency buckle for a safety belt that has an angled trap yoke attached at one end of the belt and with the yoke end suspended in a sliding member displaceable in a housing against the pressure of a spring and guided and fixed on the other end on a lower part, pivoting out sideways of the housing. There are roller with tensioning spring, and a windup roller with a gearwheel, in the sliding member. One roller runs over the holding band guided via the trap yoke, and a release lever engages the gearwheel and strikes with its other end against a pin fixed on the side toward the spring in the housing. The buckled belt automatically opens after a severe accident and releases the injured person. However, the release lever is activated only upon a given force operated on the spring controlling it hence, the weight of the injured person must be of a given magnitude to operate the release portion of the apparatus, or the impact must be of sufficient strength with an individual having a given weight to overcome the spring force. Hence, the Metz apparatus is totally unadjustable to accommodate for light impact for lightweight individuals utilizing the apparatus.
U.S. Pat. No. 3,362,748 issued on Jan. 9, 1968 to A. G. Carter describes an adjustable vehicle seat belt and seat belt combination that has a normally locked manually contoured positioning mechanism for the seat and a normally locked drum connected to the seat belt. There is communicating means interrelated between the seat belt adjusting mechanism and the seat belt drum member whereby release of the normally locked seat mechanism also releases the normally locked seat drum belt. This apparatus is quite useful in permitting the individual utilizing the belt portion to stretch the stored portion outwardly from the seat belt drum once the seat belt apparatus is separated, by a locking, from the other portions of the seat belt apparatus. However, this device, though sensibly self-adjusting as to the amount of belt tension exerted around the girth of a user, fails to provide an automatically releasable apparatus or an automatic opening apparatus upon impact which enables an injured person to escape with ease from the encircling and entrapping character of a closed belt system no matter how loose it is.